# Copyright (C) 2005, 2007 Canonical Ltd
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

# TODO: Move this into builtins

# TODO: 'bzr resolve' should accept a directory name and work from that
# point down

import os

from bzrlib.lazy_import import lazy_import
lazy_import(globals(), """
import errno

from bzrlib import (
    builtins,
    commands,
    errors,
    osutils,
    rio,
    trace,
    )
""")
from bzrlib.option import Option


CONFLICT_SUFFIXES = ('.THIS', '.BASE', '.OTHER')


class cmd_conflicts(commands.Command):
    """List files with conflicts.

    Merge will do its best to combine the changes in two branches, but there
    are some kinds of problems only a human can fix.  When it encounters those,
    it will mark a conflict.  A conflict means that you need to fix something,
    before you should commit.

    Conflicts normally are listed as short, human-readable messages.  If --text
    is supplied, the pathnames of files with text conflicts are listed,
    instead.  (This is useful for editing all files with text conflicts.)

    Use bzr resolve when you have fixed a problem.

    See also bzr resolve.
    """
    takes_options = [
            Option('text',
                   help='List paths of files with text conflicts.'),
        ]

    def run(self, text=False):
        from bzrlib.workingtree import WorkingTree
        wt = WorkingTree.open_containing(u'.')[0]
        for conflict in wt.conflicts():
            if text:
                if conflict.typestring != 'text conflict':
                    continue
                self.outf.write(conflict.path + '\n')
            else:
                self.outf.write(str(conflict) + '\n')


class cmd_resolve(commands.Command):
    """Mark a conflict as resolved.

    Merge will do its best to combine the changes in two branches, but there
    are some kinds of problems only a human can fix.  When it encounters those,
    it will mark a conflict.  A conflict means that you need to fix something,
    before you should commit.

    Once you have fixed a problem, use "bzr resolve" to automatically mark
    text conflicts as fixed, resolve FILE to mark a specific conflict as
    resolved, or "bzr resolve --all" to mark all conflicts as resolved.

    See also bzr conflicts.
    """
    aliases = ['resolved']
    takes_args = ['file*']
    takes_options = [
            Option('all', help='Resolve all conflicts in this tree.'),
            ]
    def run(self, file_list=None, all=False):
        from bzrlib.workingtree import WorkingTree
        if all:
            if file_list:
                raise errors.BzrCommandError("If --all is specified,"
                                             " no FILE may be provided")
            tree = WorkingTree.open_containing('.')[0]
            resolve(tree)
        else:
            tree, file_list = builtins.tree_files(file_list)
            if file_list is None:
                un_resolved, resolved = tree.auto_resolve()
                if len(un_resolved) > 0:
                    trace.note('%d conflict(s) auto-resolved.', len(resolved))
                    trace.note('Remaining conflicts:')
                    for conflict in un_resolved:
                        trace.note(conflict)
                    return 1
                else:
                    trace.note('All conflicts resolved.')
                    return 0
            else:
                resolve(tree, file_list)


def resolve(tree, paths=None, ignore_misses=False, recursive=False):
    """Resolve some or all of the conflicts in a working tree.

    :param paths: If None, resolve all conflicts.  Otherwise, select only
        specified conflicts.
    :param recursive: If True, then elements of paths which are directories
        have all their children resolved, etc.  When invoked as part of
        recursive commands like revert, this should be True.  For commands
        or applications wishing finer-grained control, like the resolve
        command, this should be False.
    :ignore_misses: If False, warnings will be printed if the supplied paths
        do not have conflicts.
    """
    tree.lock_tree_write()
    try:
        tree_conflicts = tree.conflicts()
        if paths is None:
            new_conflicts = ConflictList()
            selected_conflicts = tree_conflicts
        else:
            new_conflicts, selected_conflicts = \
                tree_conflicts.select_conflicts(tree, paths, ignore_misses,
                    recursive)
        try:
            tree.set_conflicts(new_conflicts)
        except errors.UnsupportedOperation:
            pass
        selected_conflicts.remove_files(tree)
    finally:
        tree.unlock()


def restore(filename):
    """\
    Restore a conflicted file to the state it was in before merging.
    Only text restoration supported at present.
    """
    conflicted = False
    try:
        osutils.rename(filename + ".THIS", filename)
        conflicted = True
    except OSError, e:
        if e.errno != errno.ENOENT:
            raise
    try:
        os.unlink(filename + ".BASE")
        conflicted = True
    except OSError, e:
        if e.errno != errno.ENOENT:
            raise
    try:
        os.unlink(filename + ".OTHER")
        conflicted = True
    except OSError, e:
        if e.errno != errno.ENOENT:
            raise
    if not conflicted:
        raise errors.NotConflicted(filename)


class ConflictList(object):
    """List of conflicts.

    Typically obtained from WorkingTree.conflicts()

    Can be instantiated from stanzas or from Conflict subclasses.
    """

    def __init__(self, conflicts=None):
        object.__init__(self)
        if conflicts is None:
            self.__list = []
        else:
            self.__list = conflicts

    def is_empty(self):
        return len(self.__list) == 0

    def __len__(self):
        return len(self.__list)

    def __iter__(self):
        return iter(self.__list)

    def __getitem__(self, key):
        return self.__list[key]

    def append(self, conflict):
        return self.__list.append(conflict)

    def __eq__(self, other_list):
        return list(self) == list(other_list)

    def __ne__(self, other_list):
        return not (self == other_list)

    def __repr__(self):
        return "ConflictList(%r)" % self.__list

    @staticmethod
    def from_stanzas(stanzas):
        """Produce a new ConflictList from an iterable of stanzas"""
        conflicts = ConflictList()
        for stanza in stanzas:
            conflicts.append(Conflict.factory(**stanza.as_dict()))
        return conflicts

    def to_stanzas(self):
        """Generator of stanzas"""
        for conflict in self:
            yield conflict.as_stanza()

    def to_strings(self):
        """Generate strings for the provided conflicts"""
        for conflict in self:
            yield str(conflict)

    def remove_files(self, tree):
        """Remove the THIS, BASE and OTHER files for listed conflicts"""
        for conflict in self:
            if not conflict.has_files:
                continue
            for suffix in CONFLICT_SUFFIXES:
                try:
                    osutils.delete_any(tree.abspath(conflict.path+suffix))
                except OSError, e:
                    if e.errno != errno.ENOENT:
                        raise

    def select_conflicts(self, tree, paths, ignore_misses=False,
                         recurse=False):
        """Select the conflicts associated with paths in a tree.

        File-ids are also used for this.
        :return: a pair of ConflictLists: (not_selected, selected)
        """
        path_set = set(paths)
        ids = {}
        selected_paths = set()
        new_conflicts = ConflictList()
        selected_conflicts = ConflictList()
        for path in paths:
            file_id = tree.path2id(path)
            if file_id is not None:
                ids[file_id] = path

        for conflict in self:
            selected = False
            for key in ('path', 'conflict_path'):
                cpath = getattr(conflict, key, None)
                if cpath is None:
                    continue
                if cpath in path_set:
                    selected = True
                    selected_paths.add(cpath)
                if recurse:
                    if osutils.is_inside_any(path_set, cpath):
                        selected = True
                        selected_paths.add(cpath)

            for key in ('file_id', 'conflict_file_id'):
                cfile_id = getattr(conflict, key, None)
                if cfile_id is None:
                    continue
                try:
                    cpath = ids[cfile_id]
                except KeyError:
                    continue
                selected = True
                selected_paths.add(cpath)
            if selected:
                selected_conflicts.append(conflict)
            else:
                new_conflicts.append(conflict)
        if ignore_misses is not True:
            for path in [p for p in paths if p not in selected_paths]:
                if not os.path.exists(tree.abspath(path)):
                    print "%s does not exist" % path
                else:
                    print "%s is not conflicted" % path
        return new_conflicts, selected_conflicts


class Conflict(object):
    """Base class for all types of conflict"""

    has_files = False

    def __init__(self, path, file_id=None):
        self.path = path
        # warn turned off, because the factory blindly transfers the Stanza
        # values to __init__ and Stanza is purely a Unicode api.
        self.file_id = osutils.safe_file_id(file_id, warn=False)

    def as_stanza(self):
        s = rio.Stanza(type=self.typestring, path=self.path)
        if self.file_id is not None:
            # Stanza requires Unicode apis
            s.add('file_id', self.file_id.decode('utf8'))
        return s

    def _cmp_list(self):
        return [type(self), self.path, self.file_id]

    def __cmp__(self, other):
        if getattr(other, "_cmp_list", None) is None:
            return -1
        return cmp(self._cmp_list(), other._cmp_list())

    def __hash__(self):
        return hash((type(self), self.path, self.file_id))

    def __eq__(self, other):
        return self.__cmp__(other) == 0

    def __ne__(self, other):
        return not self.__eq__(other)

    def __str__(self):
        return self.format % self.__dict__

    def __repr__(self):
        rdict = dict(self.__dict__)
        rdict['class'] = self.__class__.__name__
        return self.rformat % rdict

    @staticmethod
    def factory(type, **kwargs):
        global ctype
        return ctype[type](**kwargs)

    @staticmethod
    def sort_key(conflict):
        if conflict.path is not None:
            return conflict.path, conflict.typestring
        elif getattr(conflict, "conflict_path", None) is not None:
            return conflict.conflict_path, conflict.typestring
        else:
            return None, conflict.typestring


class PathConflict(Conflict):
    """A conflict was encountered merging file paths"""

    typestring = 'path conflict'

    format = 'Path conflict: %(path)s / %(conflict_path)s'

    rformat = '%(class)s(%(path)r, %(conflict_path)r, %(file_id)r)'
    def __init__(self, path, conflict_path=None, file_id=None):
        Conflict.__init__(self, path, file_id)
        self.conflict_path = conflict_path

    def as_stanza(self):
        s = Conflict.as_stanza(self)
        if self.conflict_path is not None:
            s.add('conflict_path', self.conflict_path)
        return s


class ContentsConflict(PathConflict):
    """The files are of different types, or not present"""

    has_files = True

    typestring = 'contents conflict'

    format = 'Contents conflict in %(path)s'


class TextConflict(PathConflict):
    """The merge algorithm could not resolve all differences encountered."""

    has_files = True

    typestring = 'text conflict'

    format = 'Text conflict in %(path)s'


class HandledConflict(Conflict):
    """A path problem that has been provisionally resolved.
    This is intended to be a base class.
    """

    rformat = "%(class)s(%(action)r, %(path)r, %(file_id)r)"

    def __init__(self, action, path, file_id=None):
        Conflict.__init__(self, path, file_id)
        self.action = action

    def _cmp_list(self):
        return Conflict._cmp_list(self) + [self.action]

    def as_stanza(self):
        s = Conflict.as_stanza(self)
        s.add('action', self.action)
        return s


class HandledPathConflict(HandledConflict):
    """A provisionally-resolved path problem involving two paths.
    This is intended to be a base class.
    """

    rformat = "%(class)s(%(action)r, %(path)r, %(conflict_path)r,"\
        " %(file_id)r, %(conflict_file_id)r)"

    def __init__(self, action, path, conflict_path, file_id=None,
                 conflict_file_id=None):
        HandledConflict.__init__(self, action, path, file_id)
        self.conflict_path = conflict_path
        # warn turned off, because the factory blindly transfers the Stanza
        # values to __init__.
        self.conflict_file_id = osutils.safe_file_id(conflict_file_id,
                                                     warn=False)

    def _cmp_list(self):
        return HandledConflict._cmp_list(self) + [self.conflict_path,
                                                  self.conflict_file_id]

    def as_stanza(self):
        s = HandledConflict.as_stanza(self)
        s.add('conflict_path', self.conflict_path)
        if self.conflict_file_id is not None:
            s.add('conflict_file_id', self.conflict_file_id.decode('utf8'))

        return s


class DuplicateID(HandledPathConflict):
    """Two files want the same file_id."""

    typestring = 'duplicate id'

    format = 'Conflict adding id to %(conflict_path)s.  %(action)s %(path)s.'


class DuplicateEntry(HandledPathConflict):
    """Two directory entries want to have the same name."""

    typestring = 'duplicate'

    format = 'Conflict adding file %(conflict_path)s.  %(action)s %(path)s.'


class ParentLoop(HandledPathConflict):
    """An attempt to create an infinitely-looping directory structure.
    This is rare, but can be produced like so:

    tree A:
      mv foo/bar
    tree B:
      mv bar/foo
    merge A and B
    """

    typestring = 'parent loop'

    format = 'Conflict moving %(conflict_path)s into %(path)s.  %(action)s.'


class UnversionedParent(HandledConflict):
    """An attempt to version an file whose parent directory is not versioned.
    Typically, the result of a merge where one tree unversioned the directory
    and the other added a versioned file to it.
    """

    typestring = 'unversioned parent'

    format = 'Conflict because %(path)s is not versioned, but has versioned'\
             ' children.  %(action)s.'


class MissingParent(HandledConflict):
    """An attempt to add files to a directory that is not present.
    Typically, the result of a merge where THIS deleted the directory and
    the OTHER added a file to it.
    See also: DeletingParent (same situation, reversed THIS and OTHER)
    """

    typestring = 'missing parent'

    format = 'Conflict adding files to %(path)s.  %(action)s.'


class DeletingParent(HandledConflict):
    """An attempt to add files to a directory that is not present.
    Typically, the result of a merge where one OTHER deleted the directory and
    the THIS added a file to it.
    """

    typestring = 'deleting parent'

    format = "Conflict: can't delete %(path)s because it is not empty.  "\
             "%(action)s."


class NonDirectoryParent(HandledConflict):
    """An attempt to add files to a directory that is not a director or
    an attempt to change the kind of a directory with files.
    """

    typestring = 'non-directory parent'

    format = "Conflict: %(path)s is not a directory, but has files in it."\
             "  %(action)s."

ctype = {}


def register_types(*conflict_types):
    """Register a Conflict subclass for serialization purposes"""
    global ctype
    for conflict_type in conflict_types:
        ctype[conflict_type.typestring] = conflict_type


register_types(ContentsConflict, TextConflict, PathConflict, DuplicateID,
               DuplicateEntry, ParentLoop, UnversionedParent, MissingParent,
               DeletingParent, NonDirectoryParent)
